Handheld extruder welding devices are familiar devices, and are used primarily for welding plastic panels or similar objects. Such devices consist essentially of a handheld drill serving as the drive system and a removable attachment for this drill. In the attachment, a strand of plastic in the shape of a plastic wire that is supplied via a feed channel and a feed device is first chopped up, and is then plasticized by means of a screw and a heating device. A welding device of this type is known from DE-A-28 23 171, for example.
These familiar handheld extruder welding devices, also known from EP-A 1 023 948 or EP-B 0 637 497, have a feed channel that extends, at least partially, over the length of the feed zone of the extrusion screw and has the shape of a chute, and serves to put the plastic welding wire in contact with the feed screw.
In all known handheld extruder welding devices, twisting of the plastic welding wire is a problem because, due to the rotation of the extrusion screw, the plastic welding wire is twisted around its longitudinal axis, in addition to its previous twisting caused by its unwinding from a spool device. This causes undesirable loops and twists that make it harder to handle and may require an interruption of the welding process in order to eliminate the loops.